obama stopped short of saying flatly that it's a deal breaker if republicans insist on keeping tax rates for the rich where they are now. >> i'm less concerned about red lines, per se. what i'm concerned about is not finding ourselves in a situation where the wealthy aren't paying more or aren't paying as much they should. middle-class families, one way or another, are making up the difference. >> reporter: mr. obama also faced questions on the other major story in washington right now, the extra-marital affair that ended david petraeus' career as c.i.a. director. today, he said he's seen no evidence that national security was compromised. >> obviously, there's an ongoing investigation. i don't want to comment on the specifics of the investigation. the f.b.i. has its own protocols in terms of how they proceed. we are safer because of the work that dave petraeus has done. and my main hope right now is-- is that he and his family are able to move on and that this ends up being a single side note on what has otherwise been an extraordinary career. >> reporter: the president was pressed on w